Abstract
A dynamical model of the activated sludge wastewater treatment process is presented and discussed. This modelling exercise is motivated by on-line process control and time-varying management. As a result, a comprehensive and yet simple model is proposed which stresses the interactions among various concurrent subprocesses. In this sense, it represents a balance with respect to existing models, whose enhanced describing capabilities are confined to a specific subprocess. Simulations are presented to introduce and discuss the relevant features of the model.